Image of a brain cheering


A fun, free platform for learning modern cryptography

Image of a cloud pouring information into a head

Learn By Doing

Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.

Level up image of a warrior

Level Up

Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?

New ideas in development

Fresh Challenges

We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.

New Challenges
Blind (ECSC 2023 (Norway)) CTF Archive 0
WOTS Up (ECSC 2023 (Norway)) CTF Archive 0
Irish flan (ECSC 2023 (Norway)) CTF Archive 0
WOTS Up 2 (ECSC 2023 (Norway)) CTF Archive 0
Twist and shout (ECSC 2023 (Norway)) CTF Archive 0
Weekly Top Users
#1 Joe_syn 5575
#2 dys4nt 4095
#3 Tt123N 3285
#4 AdityaDuggal 3215
#5 Manav11 3010
Recent Solves
You either know, XOR you don't K55A
Extended GCD kodeythomas
Lazy CBC Skinbow
Script Kiddie ThinkInTheBox
Finding Flags smallfry
Recent Solutions
Modular Arithmetic 1 werePhilosoper 0
Extended GCD werePhilosoper 0
Null or Never twelho 0
Passwords as Keys Ubertech 0
Broken RSA zenobia 1

Level Up

level up icon

You are now level Current level